evens only pls would you produce a 10-1 dilution of a 3 ml. bacterial sample usi

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evens only pls

would you produce a 10-1 dilution of a 3 ml. bacterial sample using the entire 3 mL vohomer le using the entire 5 mL volume? 5 You have 0.05 mL of an undiluted culture at a density of 3.6 X 10 CFU/mL. You then add 4.95 ml sterile diluent. What is the dilution and what is the final density of cells? 6 You have 0.3 mL of an undiluted culture at a density of 42 × 10, CFU/mL. You then add 2.7 mL sterile diluent. What is the dilution and what is the final density of cellst 6 What is the dilution if 96 mL of diluent is added to 4 mL of a bacterial suspension? 8 What is the dilution if 75 mL of diluent is added to 25 mL of a bacterial suspensiont 9 Yow were instructed to add 1.0mL out of S.0 mL of an undiluted sample to 99 mL of sterile diluent.Instead, you add all 5.0 mL to the 99 mlL. What was the intended dilution and what was the actual dilution? Suppose you were instructed to sample. What was the intended dilution and what was the actual dilution? 474 MICROBIOLOGY. Laboratory Theory &Application;

Explanation / Answer

4. Using the formula N1V1 = N2V2

Initial : 1; Final dilution : 10-2

Initial volume: 5 ml; Final volume; ?

Putting the known values, we get

1 X 5 = 10-2 X V2

V2 = 5/10-2 = 500 ml

Dliution = Volume added / Total volume

Thus, in order to obtain 10-2 dilution of a bacterial sample, the 5 ml of suspension is added to 495 ml diluent.

6. In such cases, to calculate the cell density, following formula is applied

C1V1 = C2V2, where, C1: Initial cell density

C2: Final cell density

V1: Initial volume of suspension

V2: Final volume of suspension

Putting the given values in the above equation;

4.2 X 107 X 0.3 = C2 X 2.7

C2 = 4.2 X 107 X 0.3/2.7 = 0.46X107

C2 = 0.46X107

Dilution = Volume added / Total volume

In the given question, Dilution = 0.3 ml / 3 ml = 1/10 = 10-1

Dilution = 10-1

8. According to the formula

Dilution = Volume added / Total volume

Dilution = 25 ml/100 ml = 1/4

i.e. Dilution = 1/4

10. As per the formula Dilution = Volume added / Total volume

Intended dilution = 0.2/10 = 1/50 = 0.02

Actual dilution = 2/11.8 = 0.169

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